Electric-arc lamp.



PATENTED APR. 11, 1905.

B. JACKISGH.

ELECTRIC ARC LAMP.

APPLIUATION FILED SEPT. 23, 1904.

w m d Z C n n a/ I E ii: 1%|}: W F AIM/ /KU IPLIP I i J 7 wq 7 F J w @af w Q vu UNITED STATES Patented April 11, 1905.

PATENT OFFICEO BRUNO. JAOKISOH, OF CHARLOTTENBURG, GERMANY, ASSIGNOR TOTHE FIRM OF ALLGEMEINE BELEUOHTUNGS UNI) I IEIZ INDUSTRTE AOTIENG-ESELLSOHAFT, OF BERLIN, GERMANY.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 787,043, dated April11, 1905.

Application filed September 23, 190 Serial No. 225,629.

To (all whom/ it rim/y concern:

Be it known that I, BRUNO JACKISCH, a subject of the King of Prussia,Emperor of Germany, residing at Oharlottenburg, Germany,

5 have invented certain new and useful Improvements in RegulatingMechanism for Are- Lamps; and .I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enableothers skilled in To the art to which it appertains to make and use thesame.

In differential arc-lamps and arc-lamps controlled by means ofshunt-coils alone the shuntcoils remain in circuit when the arc isruptured unless the entire lamp has been cut out of circuit. Thisinvolves the danger of short-circu its, more particularly in those casesin which the rupture of the arc is due to the burning away of one of thecarbons.

The object of the present invention is to provide means forautomatically cutting the shunt-coil out of circuit when the maincircuit is brokenthat is to say, when the arc is ruptured.

One form of the invention is diagran'unatically illustrated in theannexed drawing in connection with a differential arc-lamp. Itsapplication to shunt-controlled lamps will be obvious from the followingdescription.

In the drawing, the series coil is indicated by/l and the shunt-coil by'12.. These two coils act on the solenoid-cores, which is adapted tooperate the clutch r. The latter releases the upper carbon 70' when thegap has become too large and the current in the series coil has fallenbelow a certain value.

According to the present invention the shunt-circuit is not joined upwith the main circuit in a permanent manner, but includes 40 contacts aand I), which are only closed while the lamp is working. For thispurpose the contact a is rigidly connected with the solenoidcore, forinstance, by means of the rod f and the plate p. The rod f, whichcarries the contact-stud a and is adapted to move with thesolenoid-core, is of an exactly predetermined length. The contact-stud bis fixed to the short rod 0, which is adapted to move in the insulatedguide (Z and to take part, to a certain extent, in the movements of therod f. If, however, 5 the rodf'descends below a certain limit, a knob orstud 0 at the upper end of the rod cabuts against the upper surface ofthe guide (Z and stops the downward movement of the rod 0, so that a gapof a certain width is produced between the contacts a and I). By thismeans the shunt-circuit is broken, the rod 0 being connected by the wirew with the negative terminal of the lamp, and the contact a beingconnected with the shunt-coil by means of the wire 00. \Vhile the lampis working normally, the shunt-circuit is closed, whereas if from anycause the arc-circuit is broken, so that the solenoid-core completelydescends, theshuntcircuit is broken by the interrup- 5 tion of contactat a I). It is obvious that the wire w can be connected to the rod 0 instead of to the contact a, the latter being in that case connected withthe wire 10; but since the entire upper part of the arc-lamp is 7positively electric the reversal of polarity obtained by the method ofconnection shown in the diagram is neferred, since it causes the sparkproduced by the breaking of contact at (1/ 7) to be reduced to aminimum, owing to the opposite nature of the currents induced by thecollapsing oi the magnetic lields of the coils.

Having described my invention, I claim I. In an electric-arc lamp,thecombination, with a slidable upper-carbon holder, and a contact-piecesecured thereto; of a guide, a bar slidable in the said guide andprovided with a stop which limits its downward movement, a contact-piececarried by the said bar 5 and normally resting on the aforesaidcontactpiece, and a shunt-coil connected in circuit with the saidcontact-pieces so that the shuntcircuit is broken when the carbon-holderdescends to a prearranged point.

2. In an electric-are lamp, the combination, with a slidableupper-carbon holder, and a contact-piece secured thereto; of a guide, a

bar slid-able in the said guide and provided the reverse direction fromthat of the current prod ucing the are. IO

In testimony whereof I aifix my signature in presence of two Witnesses.

BRUNO JAGKISCH.

Witnesses:

HENRY HASPER, \VOLDEMAR HAUr'r.

